Fan.



J. HANRAHAN & H. A. WENDE.

FAN.

APPLICATION FILED AUG. 13, 1909.

997, 127. Patented July 4, 1911.

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HE: El E J. F. HANRAHAN & H. A. WENDE.

FAN.

APPLICATION -IILED AUG.13, 1909.

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JUSEE F. HNRHN AND HERMANN A. WENDE, 9F BUFFALO, NEW YORK; SAID WENIDE ASSEGNOR T SAID HANRAHAN.

FAN.

earner.

Specification of Letters Patent.

Patented July 4, 1911.

Application filed ugust 13, 1999. Serial No. 512,662.

more particularly designed for use in circulating air through a drier. or evaporator but which may also be used for other purposes. `0 1 rllhe object of this invention is to,produce a fan for this purpose whereby a large volume of air is positively and uniformly propelled through a conduit or passageof considerable length in the direction of the axis of the fan, as for instance, the air supply passage of a drying chamber which is equal in length to the entire length of said chamber.

ln the accompanying drawings consist-ing i of two sheets: Figure 1 is a vertical cross section of an evaporator taken in line 1 1, Fig. l and showing one application of our invention. Fig. 2 is a fragmentary horizontal section thereof on a reduced scale, in line 2 2, Fig. 1. Fig.` 3 is a horizontal section, on a reduced scale in line 3 3, Fig. 1. Fig. 4 is a vertical longitudinal section in line 4 4, Fig. 1. Fig. 5 is a'vertical cross section showing another application of our iii"- vention. Fig. 6 is a fragmentary horizontal section, on a `reduced scale, in line 6 6, Fig. 5. Fig. 7 'is a fragmentary Vertical section taken in line 7 7, Figa. Fig. 8 1s avertical section taken in line 8 8, Fig. 7.

Similar letters of reference indicate corresponding parts throughout the several views. O

.A represent-s the drying chamber which receives the products or articles to be dried and which may be of any suitable form or construction. One of the longitudinal walls of this chamber is providedadjacent to the bottom of the chamber with an air inlet thereto a and adjacent to the top thereof with an air outlet therefrom a1 said inlet and outlet of the chamber' extending horizontally the full length of the chamber vor substantially so, as shownin Figs. 3, 4 and 6. y B re resents the case of a fan which is preferably arranged outside of the wall of the chamber containing the air inlet and outlet and extending the.full length of the chamber, or substantially so, and parallel therewith. On the upper outer part of the periphery of lthe fan case the same is provided' with a tangential air inlet b which is connected by an upper inclined air conduit or plpe C with the upper air out-let of the drylng chamber. On the lower inner part of the periphery of the fan case the same is provided with a tangential air outlet b1 which isconnected by a lower horizontal air conduit or pipe D with the lower air inlet .of the drying chamber. The upper and lower conduits C, D are of the same length as the fan case and drying chamber, as shown in Figs. 3 and 4. i

Within the fan case' are arranged a plu'- ralit-y of fan blades E which rotate vertically and are mounted on a horizont-al shaft e arranged lengthwise in the fan case and driven in any suitable manner.

That-side f of the periphery of the fan case between the inner angles of the tangential inlet and outlet isarranged concentrically with the axes of the fan blades and case and the opposite side f1 of the periphery of the case between the outer angles of the tangential inlet and outlet of the fan 'case is of'scroll form or arranged eccentric'ally to the axes of the fan case and blades being of gradually increasing radii from the tangen- -tial inlet to the tangential outlet of the fan case, as shown in Fig. 1. The direction of rotation of the fan blades is such that when passing the eccentric side of theperiphery of the fan case they move from the shorter to lthe longer radii thereof.` By this means the aircarried around by the fan blades within the concentric part of the periphery of the caseis confined against outward radial movement lunder `the! centrifugal action of the fan blades4 but when the latter pass the eccentric part of the periphery `of the case the air at this time is permitted to move radially outward a limited extent and r0- duce a downward suction of the air l rom the upper part of the drying chamber through the upper air conduit and into the fan case from which latter it is again forcibly expelled through t-he lower airpipe into. the lower part of the drying chamber wherein it again rises to the top, being forcibly A'and continuously circulated in this manner so long as the fan is in operation.

In the absence of any provision to prevent it the rarefication of the air at the axis of the rotary fans due to the centrifugal action of the latter would cause a conflict of air currents at this place which would interfere with the propelling effect of the fan blades on the air for withdrawingthe same from the top of the drying chamber and returning the same to the bottom thereof. To

avoid this, means are provided whereby sufiicient air is diverted from the air inlet of the fan case to the axis of the blades to compensate for the air which is withdrawn from this location by the centrifugal action of the fan blades. The preferred means'for accomplishing this result consists in 'divid.

ing the fan yblades into a plurality of groups or sections, each group containing a clrcumferential row of blades and the several groups being arranged lengthwise side by side on the fan shaft, as shown inFig. 4c,

and providing auxiliary airsupply conduits l g which are arranged adjacent to the ends of the groups of the `fan blades and each of which extends from the air inlet of the fan -case to the axis of the blades. These auxiliary air conduits are formed by vertical partitions or diaphragms g1 arranged in the fan case between the groups of blades and 'extending yfrom the inlet to the outlet therei rents and enabling a large volume of airto the'apparatus and loss "of uniformity in the,

be propelled by the fan with the expenditure of comparatively little power.

By meansl of this fan, a uniform draft of air into the upper air conduit and a uniform blast of air from the lower air conduit is.

produced throughout the entire length of these conduits which causes a current of air of equal uniformity to rise fromy the lower to the upper part of the drying chamber and thereby operate'l alike on the products in all parts of this chamber, thereby avoiding the necessity of redrying of part of the products in a charge as has `been customary here' tofore with consequent loss of eiiiciency in product put out.

The vapors which are taken u by the air in passing the products to, be -dried are conf.

densed by intercepting vthe aii' by means of a condenser on its way to the fan which con'- denser preferably consists of water conducting coils K-which are arranged in front of the upper air outlet of the chamber and vfrom which the water of condensation drips upon a gutter or receptacle.

The air freed fromvapors upon be1ng\re pan Z leading to a sewer or rturned to the lower part of the drying chamshown in Figs. l and 3, or similar pipes or coils m1 may be arranged in the lower air conduit, as shown in Figs. 5 `and 6. The coils m, m1 may be heated by circulating a suitable heating agent through the same such as steam or hot water.

It is of course understood that the propelling effect of the fan is aided by the natural tendency of the cool column of 'air in the upper and lower air'conduit and fan case to descend by4 gravity and the hot or warm air in the drying chamber to rise. When, however,the article or product to be dried requires treatment under comparatively low temperatures, asis the case in drying vof glue and similar material, the thermal action of the air, if solely depended on, would produce a comparatively slow circulation of the air which would prolong the period of drying in' the same measure. By the use of the fan, however, the movement of the air is accelerated and the drying op- `eration expedited, thereby materially 1n.

creasing the output of' the evaporator and reducing Cthe 4cost of operation.

We claim as our invention:

`A fan comprising a circular case composed of a plurality of sections arranged axially in line, an air inlet conduit connected tangentiallyfwith the .peripheries o f said several case sections on one side thereof, an air outlet conduit vconnected with the peripheries of said several case sections on lthe opposite side thereof, auxiliary air conduits -arranged at' the ends of the several case sections and'extending fromsald lnlet conduit to said case sections at the axes thereof, fan blades rotatable in each of said case sections, 4and a shaft for driving said blades extending lengthwise through said case sections and auxiliary conduits.

Witness our hands this 12th day of August, 1909.

JOSEPH F. HANRAHAN. HERMANN A. WENDE.

f Witnesses THEO.- L. Porr, v ANNAy HErGIs. 

